Headband



FIG. 1 is a front view of an ornamental design for a headband.

FIG. 2 is a side view of the headband of FIG. 1; and,

FIG. 3 is a side view of the headband of FIG. 1 in use.

The broken lines in the figures are for environmental purposes only and form no part of the claimed design. 

The ornamental design for headband, as shown and described. 